This invention relates to object handling devices wherein objects such as magnetic tapes, documents, books, mechanical or electrical parts and others are automatically handled, for example, automatically storaged, and retrieved, automatically selected, automatically identified or so on and, in particular, to a code mark reading devices used in such object handling devices.
Automatic object storage and retrieval apparatus have been known in the prior art, as disclosed in U.S. Pat. No. 3,526,326 and others.
The apparatus of this type generally comprises at least one object transferring device to transfer the object to a desired storage location, means for detecting instant positions of the object transferring device, means for inputting an information of the desired storage location and control means for controlling the movement of the object transferring device comparing the instant position and the input information.
In many apparatus known in the prior art, the object transferring device is provided with an extractor or pick-up device for extracting or drawing the object to the object transferring device and discharging or pushing out object therefrom.
In U.S. Pat. No. 3,526,326, such an object transferring device comprises a horizontally moved carriage and a platform vertically moving on the carriage. The carriage and platform are provided with scanners or read heads for reading out horizontally and vertically arranged code marks identifying respective storage locations. The signals read out by the read heads are compared with an address code signals input by, for example, a keyboard, and the carriage and platform are moved until both signals are consisted with one another. The platform is also provided with an extractor for extracting an object into the platform from a storage location and returning an object into a storage location from the platform.
There have been known other various arrangement of the object transferring device and various control systems for the controlled movement of the device.
In those known storage and retrieval apparatus, when the electric power supply is interrupted in the way of the storage operation, the apparatus cannot continue further operation even after the electric power supply is recovered because the input information is vanished by the interruption of the power supply.
It results to high cost of the device to use a memory in the control circuit which maintains the memorized contents even if the power supply is interrupted.
It is desired that even if the power supply is interrupted, the storaging operation is continued after the recovery of power supply, without the use of such as a memory of the higher cost.
It has been known in the prior art to affix code marks on objects to identify respective objects. For example, bar codes are deposited on a surface of objects, and they are read out by use of light pens. Automatic devices of various types for reading out bar codes are also known in prior arts. But, it has been impossible in known automatic code reading devices to read out without failure a code mark on an axial end surface of an object having a circular section, or a circular plate body, a cylindrical body or the like, such as a magnetic tape holder or case, because the object cannot be always oriented so that the code mark is registered to read heads of the device.